<template>
  <div class="goods">
    <!-- 左侧的分类菜单 -->
    <div class="menu-wrapper" ref="menuWrapper">
      <ul>
        <li
          v-for="(item,index) in goods"
          class="menu-item"
          :class="{'current':currentIndex===index}"
          @click="selectMenu(index)"
        >
          <span class="text border-1px">
            <span v-show="item.type>0" class="icon" :class="classMap[item.type]"></span>
            {{item.name}}
          </span>
        </li>
      </ul>
    </div>
    <!-- 右侧的商品 -->
    <div class="foods-wrapper" ref="foodsWrapper">
      <ul>
        <li v-for="item in goods" class="food-list food-list-hook">
          <h1 class="title">{{item.name}}</h1>
          <ul>
            <li v-for="food in item.foods" class="food-item border-1px">
              <div class="icon" @click="selectFood(food)">
                <img width="57" height="57" :src="food.icon" alt />
              </div>
              <div class="content">
                <h2 class="name">{{food.name}}</h2>
                <p class="desc">{{food.description}}</p>
                <div class="extra">
                  <span class="count">月售{{food.sellCount}}份</span>
                  <span>好评率{{food.rating}}%</span>
                </div>
                <div class="price">
                  <span class="now">￥{{food.price}}</span>
                  <span class="old" v-show="food.oldPrice">￥{{food.oldPrice}}</span>
                </div>
                <div class="cartcontrol-wrapper">
                  <cartcontrol :food="food"></cartcontrol>
                </div>
              </div>
            </li>
          </ul>
        </li>
      </ul>
    </div>
    <!-- 购物车 -->
    <shopcart
      ref="shopcart"
      :delivery-price="seller.deliveryPrice"
      :min-price="seller.minPrice"
      :select-foods="selectFoods"
    ></shopcart>
    <!-- 商品详情页 -->
    <food :food="selectedFood" ref="food"></food>
  </div>
</template>

<script>
import { request } from "../../network/request";
//引入滚动库
import BScroll from "better-scroll";
import food from "../food/food";
import shopcart from "../shopcart/shopcart";
import cartcontrol from "../cartcontrol/cartcontrol";

export default {
  data() {
    return {
      goods: [],
      ratings: [],
      seller: {},
      listHeight: [],
      scrollY: 0,
      selectedFood: {},
    };
  },
  components: {
    food,
    shopcart,
    cartcontrol,
  },
  created() {
    this.classMap = ["decrease", "discount", "guarantee", "invoice", "special"];
    //调用数据
    request().then((res) => {
      // console.log(res);
      this.goods = res.data.goods;
      this.ratings = res.data.ratings;
      this.seller = res.data.seller;
      this.$nextTick(() => {
        // 初始化better_scroll
        this._initScroll();
        // 计算所有商品高度
        this._calculateHeight();
      });
    });
    //  监听来自子组件的事件
    this.$root.$on("cart.add", (el) => {
      // console.log(666);
      //防止卡顿 异步执行下落动画 优化
      this.$nextTick(() => {
        this.$refs.shopcart.drop(el);
      });
    });
  },
  computed: {
    //滚动后在哪个区域
    currentIndex() {
      for (let i = 0; i < this.listHeight.length; i++) {
        let height1 = this.listHeight[i];
        let height2 = this.listHeight[i + 1];
        if (!height2 || (this.scrollY >= height1 && this.scrollY < height2)) {
          return i;
        }
      }
      return 0;
    },

    //使购物车和加减商品联系起来
    selectFoods() {
      let foods = [];
      this.goods.forEach((good) => {
        good.foods.forEach((food) => {
          if (food.count) {
            foods.push(food);
          }
        });
      });
      return foods;
    },
  },
  methods: {
    // _initScroll() {
    //   this.menuScroll = new BScroll(this.$els.menuWrapper, {});

    //   this.foodsScroll = new BScroll(this.$els.foodsWrapper, {});
    // },
    // 初始化BScroll实例
    _initScroll() {
      // 获取需要滚动的DOM
      this.menuScroll = new BScroll(this.$refs.menuWrapper, {
        // better-scroll默认是阻止浏览器的行为，这里开放click事件
        click: true,
      });
      this.foodsScroll = new BScroll(this.$refs.foodsWrapper, {
        // 传入的参数表示实时监测滚动的位置
        // 打开本区域的点击事件监听
        click: true,
        probeType: 3,
      });
      this.foodsScroll.on("scroll", (pos) => {
        this.scrollY = Math.abs(Math.round(pos.y));
      });
    },

    //计算高度
    _calculateHeight() {
      let foodList = this.$refs.foodsWrapper.getElementsByClassName(
        "food-list-hook"
      );
      let height = 0;
      this.listHeight.push(height);
      for (let i = 0; i < foodList.length; i++) {
        let item = foodList[i];
        height += item.clientHeight;
        this.listHeight.push(height);
      }
    },

    //点击事件
    selectMenu(index) {
      //直接点击无效 因为betterscroll把默认事件取消掉了  所以要去设置
      // console.log(index);
      let foodList = this.$refs.foodsWrapper.getElementsByClassName(
        "food-list-hook"
      );
      let el = foodList[index];
      this.foodsScroll.scrollToElement(el, 200);
    },

    //商品详情
    selectFood(food) {
      this.selectedFood = food;
      this.$refs.food.show();
    },
  },
};
</script>

<style lang="stylus" rel="stylesheet/stylus">
@import '../../common/stylus/mixins.styl';
@import '../../common/stylus/icon.css';

.goods {
  display: flex;
  position: absolute;
  top: 174px;
  bottom: 46px;
  width: 100%;
  overflow: hidden;

  .menu-wrapper {
    flex: 0 0 80px;
    width: 80px;
    background-color: #f3f5f7;

    .menu-item {
      display: table;
      height: 54px;
      width: 56px;
      line-height: 14px;
      padding: 0 12px;

      &.current {
        position: relative;
        z-index: 10;
        margin-top: -1px;
        background-color: #fff;
        font-weight: 700;

        .text {
          border-none();
        }
      }

      .icon {
        display: inline-block;
        vertical-align: top;
        width: 12px;
        height: 12px;
        margin-right: 2px;
        background-size: 12px 12px;
        background-repeat: no-repeat;

        &.decrease {
          bg-image('decrease_3');
        }

        &.discount {
          bg-image('discount_3');
        }

        &.guarantee {
          bg-image('guarantee_3');
        }

        &.invoice {
          bg-image('invoice_3');
        }

        &.special {
          bg-image('special_3');
        }
      }

      .text {
        display: table-cell;
        width: 56px;
        font-size: 12px;
        vertical-align: middle;
        border-1px(rgba(7, 17, 27, 0.1));
      }
    }
  }

  .foods-wrapper {
    flex: 1;

    .title {
      padding-left: 14px;
      height: 26px;
      line-height: 26px;
      border-left: 2px solid #d9dde1;
      font-size: 12px;
      color: rgb(147, 153, 159);
      background: #f3f5f7;
    }

    .food-item {
      display: flex;
      margin: 18px;
      padding-bottom: 18px;
      border-1px(rgba(7, 17, 27, 0.1));

      &:last-child {
        border-none();
        margin-bottom: 0;
      }

      .icon {
        flex: 0 0 57px;
        margin-right: 10px;
      }

      .content {
        flex: 1;

        .name {
          margin: 2px 0 8px 0;
          height: 14px;
          line-height: 14px;
          font-size: 14px;
          color: rgb(7, 17, 27);
        }

        .desc {
          margin-bottom: 8px;
          line-height: 12px;
          font-size: 10px;
          color: rgb(147, 153, 159);
        }

        .extra {
          line-height: 10px;
          font-size: 10px;
          color: rgb(147, 153, 159);

          .count {
            margin-right: 10px;
          }
        }

        .price {
          font-weight: 700;
          line-height: 24px;

          .now {
            margin-right: 4px;
            font-size: 14px;
            color: rgb(240, 20, 20);
          }

          .old {
            text-decoration: line-through;
            font-size: 10px;
            color: rgb(147, 153, 159);
          }
        }

        .cartcontrol-wrapper {
          position: absolute;
          right: 0;
          bottom: 10px;
        }
      }
    }
  }
}
</style>
